Poiseuille law - Lecture notes 1 PDF

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Summary

Description of Poiesuille's Law and the physiology of systemic circulation...

Description

Poiseuille’s Law Flow decreases when resistance increases and vice versa. Since resistance is proportional to blood vessel diameter, constriction of a blood vessel increases resistance and thus decreases flow. Flow =(P1 –P2)/R or (P1 –P2)r4/8vl r = radius of vessel, v = viscosity, l = length of vessel

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Rate of blood flow is directly proportional to the forth power of the radius of the vessel, which demonstrates that the diameter of a blood vessel plays the greatest role of all factors in determining the rate of blood flow through a vessel.

During exercise, the heart beats with greater force increasing pressure in the aorta. Capillaries in skeletal muscle increase in diameter decreasing resistance and increasing flow. Increased flow in the aorta can go from 5L/min to 25L/min.

Physiology of Systemic Circulation •

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Determined by –

Anatomy of circulatory system

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Dynamics of blood flow

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Regulatory mechanisms that control heart and blood vessels

Blood volume –

Most in the veins (greater compliance)

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Smaller volumes in arteries and capillaries...